The objective of this work is to present the results of the comparative analysis of YAG:Ce3+ microstructural parameters obtained from x-ray powder diffraction (XRPD) data using Rietveld based Koalariet and Fullprof programs. YAG:Ce3+ powder is obtained via low temperature aerosol route at 3200C followed by post annealing treatment. The chosen technique of synthesis, i.e. ultrasonic spray pyrolysis, provides the generation of spherically shaped and submicronically sized particles having composite nanostructure. Since the targeting garnet phase represents a very promising host phosphor material being doped with rare-earth ions, the most important criteria determining its applicability in various optical devices is the uniform distribution of the luminescent center in the host lattice as well as the cubic YAG phase crystallinity. Comparison of the data obtained for the same samples by the above mentioned XRPD analyses gives us an insight into the validity of the refined parameters.